<!DOCTYPE html> 
<html> 
<body> 
<div style="float:left; width:200px; height:50px; background:gray; border:5px solid #CCC;; margin:10px;">FLOAT</div>
<div style="clear:left; margin:-30px 10px 10px; border:5px solid black; width:200px; height:50px; background:silver; filter:alpha(opacity=50); opacity:0.5;">CLEAR</div>
</body> 
</html>